Two of the shoes on my Case 450C have hairline cracks running over halfway across. They are 16” shoes on the right side and have one shoe between them. The crack in each starts on the outside and runs over halfway. The cracks are completely through the shoe and are visible on both sides. They aren’t connected to bolt holes. The tracks have low hours. As the tracks are in otherwise great shape, I plan to remove them, weld the cracks, and reinstall. Anyone seen this before?
Yes just v out the crack on both sides and weld it
I'd weld them with 8018 to be a little stronger than 7018. A little preheat till fairly warm to the touch wouldn't hurt. Start your welds at the outside edge and work towards the center. Preferably you want to bevel each side for 100% penetration. You can weld one side then grind the other side into the weld you did. Alternate sides when welding to lessen warping. Wouldn't be a bad idea to clamp 2 of them back to back to keep them flat.
Thanks for the info!
If I could I'd leave them on the machine, if they are tight.
as long as you can get to them
Yeah they'd have to be good and tight and weld the inside after you roll it around to in front ofthe bottom of the sprocket. That's about the only place I can think of to weld the inside.
It would depend if the cracks went under the rails and you couldn't weld the full length of the crack.
He says they run about halfway in and are not connected to the bolt holes, so my guess is they are not over the rails.
Then by all means weld them on the machine. It would still be good to alternate welding on each side to limit warpage and built up stress from the welding.
Yes all of that. having them bolted to the rail helps with that too. I tend to stitch stuff like that here and there and back and again, since watertight is not a requirement.
It's quite amazing how much stress can be caused by welding or rather improper welding technique. Forgot to mention to preheat and peening helps eliminate the stresses caused by welding.
yeah, that too. I get around that by laying down no more than an inch of bead at a go and peening, go to another area and repeat, etc. I learned the hard way a few times about just how far a hot bead will pull metal, permanently
Welding in place is the way to go. It may be that the cracks relieved stress from the installation (they are replacements). I think I'll drill stress relief holes where the cracks appear to end, weld an inch on the outside of each shoe and stitch weld in between.
Drilling might be difficult. I'm not sure if track shoes would react similar to cast iron or cast aluminum where drilling the ends of cracks stops them from spreading. It couldn't hurt. Preheat would be very advantageous to limit weld stress.